The Sau Voi Corp. isn’t technically a restaurant; it’s actually a record store that stocks hundreds of top-40 Vietnamese CDs and tapes. But tucked to the side of this music emporium is a tiny counter where two women make what might be the city’s most perfect Vietnamese sandwiches. The classic Dac Biet sandwich is an explosion of vegetable brightness: incandescent carrot, bright cilantro, crisp cucumbers. Even better is the meat: ham, turkey, barbecue pork, the mysterious “Vietnamese pate” (a kind of potted pork), the even more mysterious “pork roll,” and the sublimely sweet Vietnamese meatballs. Packed into crisp, warm French bread, each sandwich runs a mere $4–which sets a record all its own in terms of culinary bargains.